The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.
Vehicle can provide comfort for human beings, but accidents concerning the operation of vehicles are still a problem to be solved. The number of deaths from automobile accidents worldwide is reported to reach 1 million every year, accidents reaching 50,000 cases.
Attempts have been made for a long time to solve the vehicle safety issues. Among them, in particular, various techniques have been studied for exchanging information between adjacent vehicles by way of vehicle-to-vehicle communication using radio frequency (RF) and controlling an actuator and a steering wheel by applying a collision avoidance algorithm based on the exchanged information.
The control technology using the collision avoidance algorithm is held from engaging automatically until a dangerous situation does occur, which gives rise to a need for a safety service provision technology that can constantly assist drivers with positive danger prevention.
Meanwhile, visible light communication is a noteworthy state-of-the-art technology which is to utilize light from a source such as LED (Light Emitting Diode) which emits light by a semiconductor as a carrier wave for carrying and transmitting information. The visible light communication utilizes visible light having a wavelength of 780 nm to 380 nm, which has the advantage of providing communications simultaneously with illumination.
Visible lighting equipment is the single element that the visible light communication needs to utilize and the head lights and taillights attached to a vehicle may be used as they are for a communication means, requiring no separate communication infrastructure or equipment. In addition, no crosstalk thanks to the straightness of the light precludes the issue of radio wave crosstalk caused by multiple vehicles, which is a drawback of existing radio frequency communication. The visible light communication can be driven with low power consumption, which makes it very suitable to be used for communication between vehicles. Moreover, the light is much more accurate than the radio waves in terms of precisely recognizing positions.
Patents have been disclosed recently concerning the safety of vehicles using such visible light communication, but there is no provision of a concrete and practical means which can be widely spread by applying visible light communication.
Korean Patent Publication No. 10-2013-0009132 (published Jan. 23, 2013) discloses a vehicle control device using visible light communication for decelerating the speed of the user's main vehicle by detecting a sudden deceleration from a preceding vehicle's speed information received through visible light communications. The disclosed device is designed to operate upon detecting a deceleration of the preceding vehicle (vehicle ahead), and therefore the preceding vehicle when perceiving a dangerous situation ahead leaves the following main vehicle incapable of counteracting immediately.
A brake pedal installed in a vehicle emits a red taillight only with the driver's operation and gives a warning to the driver of the following vehicle. In addition, the red taillight is designed to light with the same brightness regardless of the strength by which the driver operates the brake pedal. This leaves the driver of the following vehicle ignorant of any possible emergency situation lying ahead.
There are also drivers who do not operate the brake pedal with the intention of not wanting to decelerate even if their preceding vehicle has operated the brake pedal. In such a case, the following vehicle is in danger of keeping to drive with acceleration not knowing if a lead vehicle operated brake pedal or not because it was occluded by the preceding vehicles (vehicles ahead). Therefore, when an incident occurs ahead, the following vehicle operators looking only at the brake taillight of the lead vehicle risk a chain collision due to a sudden stop of the lead vehicle.
Besides such an extreme situation, with brake taillights designed to be lit upon operating the brake pedal, the driver is uninformed of details, such as whether the lead vehicle operator gently put the foot on the brake pedal. This would mislead a driver to accelerate watching only that the lead vehicles' brake taillights are not lit until the driver suddenly returns to the brake pedal operation subsequent to the lead vehicles' brake pedal operation, which leads to road safety issues.
In addition, on the side of the preceding vehicle, a suspected, but unidentifiable accelerator pedal operation of its following vehicle hinders the preceding vehicle from braking in a quick timely manner due to a concern for a rear-ending accident by that following vehicle.
Further, the general principle of making a lane change is to confirm the following vehicle in the next lane to go to, and at the same time, it is necessary to check also the preceding vehicle, so there are needs for informing the distance to the following vehicle and/or alerting the driver of the danger at the lane change.